1. Field of the Invention
With reference to the classification of art as established in the United States Patent and Trademark Office this invention pertains to the general Class entitled, "Winding and Reeling" (Class 242) and more particularly to the subclass entitled, "contractible or expansible -- with inflatable means" (subclass 72B).
2. Description of the Prior Art
Expanding chucks and mandrels are well known in the art and in particular expanding mandrels or chucks which use hydraulic fluid or air to expand and move the segments.
In particular, such devices are particularly shown in my U.S. Pat. No. 3,917,187 as issued on Nov. 4th, 1975 and in my U.S. Pat. No. 3,937,412 as issued on Feb. 10th, 1976. In both my above-identified patents the retention and expansion of the leaf members have been limited as to their expansion by means of interrelated shoulder members or in tongue and groove members. In the expanding mandrels, above-described, tension retention of the leaf members either by a garter spring or a rubber strip which engages and is mounted in grooves in the leaf members is shown. These rubber strip members are fitted to the inside grooves of the longitudinal leaf members to retain these members in the inner condition. It has been found that in the smaller expanding chucks that where the length is rather extensive the sliding in place of the last rubber strip into the grooves of the adjacent leaf member has been a problem. In the present invention the interlocked longitudinal segments used are of like metal extrusion. These extrusions are leaf members cut to length from a long extrusion length. Each leaf segment has one longitudinal edge formed as a tongue with an enlarged rounded end and the other edge is formed with an arcuate T-groove. The undersurface portion of each longitudinal segment, instead of being provided with longitudinal grooves, is smoothly finished with no provision for mounting rubber strips in grooves formed in the leaves comprising the expanding outer portion of the mandrel. After assembling, the present invention contemplates chafe-preventing strips. In the present invention the means for moving the several leaf members to their inner extent or limit are circumferential grooves that are formed in the exterior of the assembled mandrel. These circumferential grooves are formed by clamping the leaf assembly and in a lathe cutting these grooves. In these grooves are fitted garter springs or rubber O-rings, as selected.